1976 $USD RRP: $900.00
Inflation adjusted $USD RRP: $3,680.00
Considered by many to be the best receiver/amplifier of the 1970s (translates best-ever – period!) the Pioneer SX-1250 was the top-of-the-line model for the 1976-1977 Pioneer Receiver range.
A product of the “Receiver Wars” no expense was spared in the design and engineering of this model and this is evident in the specifications, build quality and performance.
Over the course of the 1970s Pioneer led the trends in terms of design and engineering of audio equipment with the majority of its major competitors shamelessly copying the styling of many Pioneer models. From the blue back light model Receivers of the early to mid-seventies to pressed aluminium silver tuning dials from the mid-seventies onwards.
In terms of aesthetics the SX/50 series design was a dramatic departure from all previous silver fascia receiver designs to date with its silver pressed tuning dial and warm yellow glow and was quickly duplicated by the likes of Kenwood, Sansui, Marantz and Sanyo. Few brands such as Yamaha and Sony stuck to their guns with their own distinct styling.
In Pioneers previous 1974-1975 product range the top-of-the-line receiver the blue-lit SX-1010 had made a world first by being the first 100 Watt RMS amplifier ever released and while the other manufacturers rushed to catchup with this beast Pioneer were slowly and deliberately planning a new monster. So when the SX-1250 was released in 1976 Pioneer again broke all previous power records boasting an enormous 160 Watts RMS per channel.
To achieve this unprecedented power rating Pioneer developed the now legendary power section of the SX-1250 with completely independent power supplies, including separate power supply windings, rectifiers and smoothing capacitors for each channel, the components of which include a massive 22 pound toroidal core transformer (less susceptible to power fluctuations and less likely to create noise than laminated core transformers) and four ‘Coke Can’ size 22,000uf filter capacitors.
The amplifier section was composed of a 2-stage differential amplifier and a Darlington push-pull amplifier for the final stage. All stages are direct coupled in a pure complementary OCL circuit that includes a current mirror circuit.
This combination delivered FTC regulation measurements of 160 Watts RMS per channel into 8 ohms from 20-20KHz with no more than 0.1 THD and 200 Watts RMS per channel with 0.1 THD into 4 ohms.
The preamplifier section combines exceptional flexibility with superb sound achieved through utilising field effect transistors and CR type integrated circuits. The phono input has a 4-stage preamplifier equaliser with an RIAA correction of only +_0.3dB and a overload level of 500mV meaning no magnetic cartridge can strain the pre-amp. The designs of these sections were directly borrowed from Pioneer’s separate components.
Pioneer never manufactured a unit to match these specifications ever again and this is one of the many reasons purists believe that this model is the apex of high fidelity sound. The now legendary SX-1980 from Pioneers 1978-1980 product range used essentially the same power supply to produce 270 Watts RMS per channel while the model intended to take over from the SX-1250, the SX-1280, had downgraded its capacitors to 15,000mfd even though it was rated 20 Watts RMS higher the the SX-1250!
This receiver was meant to be the finest available then and as it turns out it remains one of the finest available to this day.
“This unit is a must have if you can find one. I will never part with this monster. No other receiver has ever compared.” http://www.audioreview.com/cat/amplification/receivers/pioneer/sx-1250/prd_118733_1593crx.aspx#reviews
“NOTHING that I have ever owned or heard sounds as golden as my SX-1250 and the RT-707 reel-to-reel hooked up to it. The sound kind of reminds me of when I was a little boy and my father had purchased a monophonic tube amplifier from Radio Shack (there were only two Radio Shacks, one in Boston and one in my home town, New Haven. The SX-1250 beats that old tube amp for warmness and full-spectrum sound. It is also manufactured to outlast my life, and I am fifty! Can’t praise the sound or quality enough. Plus, it’s good looking. Beauty and brains!” http://www.audioreview.com/cat/amplification/receivers/pioneer/sx-1250/prd_118733_1593crx.aspx#reviews
“I spent a couple years in Germany in the late 70’s. All the guys were buying monster receivers from down @ Mainz (spelling?), so I’ve listened to a lot of different models and nothing tops this 1250. It’s got a “warmth” of sound difficult to describe and aesthetics beyond compare. All my wife’s friends pity her for having to put up with this yugo sitting in her house. If you come across one you can afford, don’t let it pass you by.” http://www.audioreview.com/cat/amplification/receivers/pioneer/sx-1250/prd_118733_1593crx.aspx#reviews
“This is hands down the best Pioneer receiver I have ever heard, the depth, clarity and power that the restoration has given it is something else, I can’t describe it, it’s something that must be heard to appreciate it. It will have a permanent place at the head of my rack, I don’t think I will ever sell it. ” http://mattsvintageaudiorepair.blogspot.com.au/2012/01/pioneer-sx-1250-score.html